The 626PA6003-1 Monitor Plug-In analyzes three channels of 50 to 600 V, 45/65Hz. The unit will monitor and record impulses, sags and surges, undervoltages, overvoltages and frequency variations (channel A only) on three channels of AC voltage. Impulse duration measurement included as standard. Accuracy 0.1Hz. Front panel features complete programmable, operational and printout functions. Input via terminal strip (barrier type).